1. Field of Art
The present invention relates generally to the field of digital information processing, and more specifically to generating and analyzing routes based on digital maps.
2. Background of the Invention
Digital maps, such as those provided by GOOGLE INC., are used in a wide variety of electronic devices, such as car navigation systems and mobile phones. Users rely on digital maps, as well as routes generated in response to queries for directions between places on the digital maps, to provide comprehensive and accurate information about roads and other geographic features for purposes including navigation and education. Therefore, the map data should be as accurate and complete as possible.
Which roads to display on a map at a particular zoom level is one area which can lead to maps being less informative than they could be. Traditionally, which roads to display has been determined by the classification of the road by a governmental entity. These classifications include interstate highways, state highways, county roads, etc. All roads within a given classification are usually shown or not shown at a particular zoom level without taking into account how the roads are actually used. For example, when looking at map of a large area, all interstate highways are shown but no county roads are shown. In fact, some county roads may be used to go long distances. Map users planning longer trips are often looking at a single map covering the entire area of their trip, but that conventionally only shows large roads like interstate highways.